Subcaliber ammunition



(No Model.)

P. J. RABBETH. SUBOALIBER AMMUNITION.

No. 587,857. Patented Aug. 10,1897.

Ryan/602",

3m cilia 35,9190,

UNITED STATES PATENT Orrica.

FRANCIS J. RABBETH, OF BOSTON, MASSACHUSETTS.

SUBCALIBER AMMUNITION.

SPECIFICATION forming part of Letters Patent No. 587,857 dated August10, 1897. Application filed March 15, 1897. Serial No. 627,664. (Nomodel.)

To (LZZ whom it In/(141 COILCCT'IL:

Be it known that I, FRANCIS J. RABBETH, of Boston,eounty of Suffolk, andState of Massachusetts, have invented an Improvement in SubcaliberAmmunition, of which the following description, in connection with theaccompanying drawings, is a specification, like letters on the drawingsrepresenting like parts.

The present invention relates to subcaliber ammunition for use in rifledguns, the object being to produce a subcaliber projectile, or

one that can be shot efficiently and accurately in a gun ofsubstantially larger caliber than the diameter of the projectile, and toutilize therewith the ordinary shell, which will properly fit thechamber of the gun, whilethe charge of powder is materially reduced.

There are frequently conditions under which it is desirable to be ableto shoot properly a smaller projectile than the one for which the gun isdesignedas, for example, in small arms used for sporting purposes whensmallgame is encountered when the sportsman has only a rifle intendedfor large game, or for military purposes to admit of target practice inan armory or elsewhere when the regular military cartridge could not beused on account of the weight and power of the projectile, although itis desirable that the practice should be with the regular arm.

Similar conditions may exist with guns of large caliber, such as areused on shipboard or in fortifications, and the present invention isequally applicable to ammunition for large ordnance, although forconvenience it is shown as embodied in a projectile for smallarms, suchas military or sporting rifles.

The invention consists, essentially, in a sectional jacket or bushing ofrelatively light material-such, for example, as woodof proper size andshape externally to fit the cartridge-shell and to take the grooves ofthe rifle like the regular projectile which is commonly used in therifle, said jacket being adapted to support the small projectileconcentric with its axis and to engage with the outer surface of saidprojectile with sufficient firmness to impart the rotary movement to thesaid projectile that is given to the said surrounding bushing or jacketby the grooves of the rifle. The said jacket, owing to its sectionalconstruction and its lightness or relatively low specific gravity, fliesapart im mediately after'leaving the muzzle of the gun, so that theflight of the small projectile is unimpeded, and experimenthas shownthat a projectile can by these means be fired with substantiallyequalaccuracy to that of a proj ectile which is itself of proper size totake the grooves of the rifle.

Figure l is a side elevation of a projectile embodying this invention;Fig. 2, a rear end elevation thereof; Fig. 3, a sectional eleva tion ofa cartridge loaded with such a project ile in accordance with thisinvention, and Fig. 4 a sectional elevation showing a modified construction of the subcaliber projectile.

The invention is shown as embodied in a subcaliber projectile for asmall-arm, such as a sporting or military rifle, for the purpose ofenabling a bullet or projectile a (see Fig. 3) of much smaller diameterthan the boreof the rifle to be shot accurately and successfully as, forexample, when it is desired to shoot a bullet adapted for a caliber oftwenty-two or twenty-five one-hundredths of an inch in a rifle ofsubstantially larger caliberas, for example, one of forty or forty-fiveone-hundredths of an inch. To this end the small bullet a is incased ina bushing or jacket I) of relatively light material, such as wood, andof external diameter and shape corresponding substantially to that ofthe projectile regularly used in the rifle, the said jacket I) beingherein shown as slightly enlarged just in front of the mouth of theshells to form a shoulder 5 which prevents the jacket from being forcedinto the shell beyond the desired position, the enlarged portion,moreover, being adapted to cooperate with the grooves of the rifling.Such construction, however, is not essential, since with quick powder itis found that in most cases the rear end of the bullet will be upsetsufficiently to force the sections of the jacket apart sufiiciently toproperly cooperate with the grooves of the r ifling. The said bushing orjacket has a central bore or recess of proper size to receive the smallbullet a snugly within it, and is compressed into firm engagementtherewith in the operation of setting the jacket and bullet in thecartridge-shell, as shown in Fig. 3, and being forced into still firmerengagement therewith by the compression due to the jacket taking therifling of the gun when shot and the upsetting effect due to thepressure of the gas and wad against the breech end of the pro jectile assoon as it leaves the muzzle of the thus made the body portion may besplit longitudinally, preferably on two planes at right angles to oneanother, as indicated at 19 Figs.

-1 and 2, the reduced portion or neck 17 preventing the splits frompassing through the collar or button b which thus serves to hold thesections of the jacket together while the bullet is introduced therein,and together therewith is introduced into the cartridge shell, afterwhich the button?) may be cut off, as indicated in Fig. 3, leaving thesections of the jacket nearly or wholly separated.

WVhile the jacket constructed as above described, with a buttonconnected with the body thereof by a thin neck to provide for thesplitting of the body without the complete separation of the sectionsthereof from one another, is convenient and efficient and is believed tobe novel and constitutes a part of this invention, this construction isnot essential to the ,main invention, as the totally 'or partiallyseparated sections of the jacket may be held together until thecartridge is prepared or the gun loaded by other temporary fastenin gsadapted to be removed before firing or in the act of firing, so that thesections of the jacket will readily separate directly afterleaviug themuzzle of the gun.

In another application, filed March 15, 1897,

Serial No. 627, 665, I have shown andd escribed a loading-tool adaptedto hold a jacket made without the button, as above described, and tomaintain the parts thereof properly assembled during the insertion ofthe bullet into the shell. Unless the jacket freely clears itself of thebullet directly as it issues from the bore of the gun there is liabilityof disturbing the flight of the bullet, so that the shooting will beinaccurate. The splitting of the jacket should therefore be such as towholly separate the sections, and by having v the forward end of thejacket project to or beyond the end of the projectile, as shown,

air is compressed in the bore of the jacket around the bullet during therapid forward movement, and thus tends to separate the sections if theyshould adhere to one another or if the grain should not be completelyseparated throughout the entire length of the meeting edges of thesection.

It is further desirable that the construction should be such that thebullet will not extend beyond the end of the jacket, because by thisconstruction the jacket affords protection for the b ullet, which mightotherwise be displaced laterally if the forward end thereof projectedbeyond the jacket, such disturbance, which would throw the bullet out ofline, being obviously objectionable, as it would result in inaccurateshooting.

In magazine-firearms, moreover, where a number of cartridges are'supported'end to end in the magazine, danger would be encountered ifthe small projectile or bullet extended beyond the end of the jacket,since it would be in contact with the primer of the adjacent cartridgeand would be liable to explode the same, owing to the recoil of the gunwhen fired. stated, moreover, that the enlarged portion or shoulder b ofthe jacket in front of the shell is of importance for the same reason,since it prevents the jacket from being forced back into the shell bythe pressure of the magazine-spring or the shock caused by the recoil ofthe gun. It is advantageous also to have the jacket tapered or roundedexternally toward its forward end, as shown, giv- In this connection itmay be ing it substantially the external form of the full-sized bulletfitted to the bore of the gun,

as the cartridge is thus entered readily into the chamber in the breechof the gun. In order to insure the equal and uniform movement of thejacket and its inclosed projectile through the bore of the gun, thejacket or projectile should be backed up by a suitable wad or gas-checkd, as shown in Fig. 3, to properly distribute the gas-pressure on thebase of the jacket .and inclosed projectile.

Since it is obviously desirable to reduce the charge of powder when asmall bullet is to be fired instead of the larger heavier bullet whichis itself adapted to fit the bore of the rifle, the ammunitionconstructed in accordance with the present invention comprises the shell0, which is of the normal or usual size and length, so as to properlyfit the chamber of the gun, the said shell containing a relatively smallcharge of powder e, which is confined by a wad 6 shown as separated fromthe projectile by a space f, it thus being apparent that while acomparatively small charge of powder is used the cartridge embodying theinvention will be substantially the same in size and shape as thecartridge loaded in the usual way and adapted for use with the gun inwhich the herein-described subcaliber ammunition is to be used.

A further feature of the invention consists in the use of a mixedpowder, this being of importance for the reason that when a small chargeof a mechanically mixed or prepared explosive, such as the so-calledblack powder, is used in a shell loaded as above deexplosive somechemically-prepared explosive, sueh as the so-called nitropowder,however, a more perfect combustion is ob- .tained and the rapid foulingof the gun to a large extent prevented. If, however, nitropowder aloneis used, although it will not rapidly foul the gun, there is liabilityto hang fire owing to the slowignition of nitropowder, this difficultybeing entirely obviated by the admixture of the ordinary gunpowder orblack powder therewith.

In the modification shown in Fig. 4: the recess in the jacket does notextend wholly through the same, and in this construction a lighter wador gas-check may be used, or in some cases no additional gas-check wouldbe required. This construction is desirable when a spherical bullet orone of comparatively small elongation is used, as is required when therifling is such as to give insuflicient rotation to steady a very muchelongated bullet.

Inorder to more thoroughly insure the rotation of the bullet with thejacket, the bullet may be provided with longitudinal grooves, as shownat a Fig. 3, in addition tothe usual circumferential groove, or may haveits outer surface otherwise roughened or prepared to interlock with orbe securely frictional] y held by the inclosing jacket; but suchconstruction is not essential, as without such grooving or rougheningthe jacket, when properly constructed, will impart the necessaryrotation to the inclosed bullet, which in practice is found to shootsubstantially as accurately as a bullet which itself fits the bore ofthe gun.

I claim 1. A jacket for adapting a bullet of small diameter toa gun oflarger caliber, composed of a piece of wood shaped externally tocorrespond in diameter with a projectile of proper size for the caliberof the gun and having at its forward end an integral button connectedwith the body portion by a reduced neck, whereby when the body portionis split longitudinally into sections the latter are temporarily heldtogether to facilitate the loading of the projectile, substantially asdescribed.

2. A jacket for a subcaliber projectile adapted to be shot from the gunwith the projectile, saidjacket being composed of longitudinal separablesections, and of proper size at the rear portion to fit thecartridge-shell, said sectional jacket having a recess concentric withits axis to receive within it the bullet and having an enlarged portionadjacent to said rear portion to cooperate with the grooves of therifling, and prevent the said jacket from being accidentally forced intothe shell beyond its normal position, substantially as described.

3. A jacket for a subcaliber projectile composed of longitudinalseparable sections, of

proper size to fit the bore of the gun, and having a recess concentricwith its axis to receive the bullet, said recess being open at itsforward end, the forward end of said jacket being tapered or roundedexternally and extending forward as far as the end of the bullet,substantially as and for the purpose described.

4. Subcaliber ammunition comprising a cartridge-shell containing as acharge a mixture of chemically-prepared explosive andmechanically-prepared explosive, a Wad adapted to confine the saidcharge, a bullet of relativelysmall caliber provided with a jacketadapted to fit the cartridge-shell and conform to the bore of the gun,and made of separable sections of relatively light material, the saidjacketed bullet being separated from the said wad by an air-space andthe jacket thereof extending forward as far as the end of the bullet andbeing tapered externally, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FRANCIS J. RABBETH.

Witnesses:

H. J. LIVERMORE, NANCY P. FORD.

